[v2,1/2] strdup: Add tests (BZ #30266)

Copy strcpy tests for strdup.  Covers some basic testcases with random
strings.  Add a zero-length string testcase.

Signed-off-by: Joe Simmons-Talbott <josimmon@redhat.com>
---
 string/Makefile      |   1 +
 string/test-strdup.c | 241 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 242 insertions(+)
 create mode 100644 string/test-strdup.c

On 30/03/23 11:50, Joe Simmons-Talbott via Libc-alpha wrote:
> Copy strcpy tests for strdup.  Covers some basic testcases with random
> strings.  Add a zero-length string testcase.
> 
> Signed-off-by: Joe Simmons-Talbott <josimmon@redhat.com>
> ---
>  string/Makefile      |   1 +
>  string/test-strdup.c | 241 +++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 242 insertions(+)
>  create mode 100644 string/test-strdup.c
> 
> diff --git a/string/Makefile b/string/Makefile
> index c84b49aaa5..472e318aea 100644
> --- a/string/Makefile
> +++ b/string/Makefile
> @@ -157,6 +157,7 @@ tests := \
>    test-strcmp \
>    test-strcpy \
>    test-strcspn \
> +  test-strdup \
>    test-strlen \
>    test-strncasecmp \
>    test-strncat \
> diff --git a/string/test-strdup.c b/string/test-strdup.c
> new file mode 100644
> index 0000000000..04eedafc24
> --- /dev/null
> +++ b/string/test-strdup.c
> @@ -0,0 +1,241 @@
> +/* Test and measure strdup functions.
> +   Copyright (C) 2023 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +		  //

Spurious '//'.

> +#include <support/check.h>
> +
> +#ifdef WIDE
> +# include <wchar.h>
> +# define CHAR wchar_t
> +# define UCHAR wchar_t
> +# define sfmt "ls"
> +# define BIG_CHAR WCHAR_MAX
> +# define SMALL_CHAR 1273
> +# define STRCMP wcscmp
> +# define MEMCMP wmemcmp
> +# define MEMSET wmemset
> +#else
> +# define CHAR char
> +# define UCHAR unsigned char
> +# define sfmt "s"
> +# define BIG_CHAR CHAR_MAX
> +# define SMALL_CHAR 127
> +# define STRCMP strcmp
> +# define MEMCMP memcmp
> +# define MEMSET memset
> +#endif
> +
> +#ifndef STRDUP_RESULT
> +# define STRDUP_RESULT(dst, len) dst
> +# define TEST_MAIN
> +# ifndef WIDE
> +#  define TEST_NAME "strdup"
> +# else
> +#  define TEST_NAME "wcsdup"
> +# endif
> +# include "test-string.h"
> +# ifndef WIDE
> +#  define STRDUP strdup
> +# else
> +#  define STRDUP wcsdup
> +# endif
> +
> +IMPL (STRDUP, 1)

There is no need to use IMPL here, no architecture provides strdup ifunc
variants.

> +
> +/* Also check the generic implementation.  */
> +#undef STRDUP
> +#undef libc_hidden_builtin_def
> +#define libc_hidden_builtin_def(a)
> +#undef libc_hidden_def
> +#define libc_hidden_def(a)
> +#undef weak_alias
> +#define weak_alias(a,b)
> +#undef attribute_hidden
> +#define attribute_hidden
> +#endif

This is also not required (it is essentially dead definitions).

> +
> +typedef CHAR *(*proto_t) (const CHAR *);
> +
> +static void
> +do_zero_len_test (void)
> +{
> +  char src[1] = { '\0' };
> +  char *dst = strdup (src);
> +
> +  TEST_COMPARE_STRING (dst, src);

Since you are testing the interface, also call free here (and it avoid
leak reports on memory profiling tools).

> +}
> +
> +static void
> +do_one_test (const CHAR *src,
> +	     size_t len __attribute__((unused)))
> +{
> +  char *dst = strdup (src);
> +
> +  if (STRCMP (dst, src) != 0)
> +    {
> +      error (0, 0,
> +	     "Wrong result in function strdup dst \"%" sfmt "\" src \"%" sfmt "\"",
> +	     dst, src);
> +      ret = 1;
> +      return;
> +    }
> +}
> +
> +static void
> +do_test (size_t align1, size_t align2, size_t len, int max_char)
> +{
> +  size_t i;
> +  CHAR *s1;
> +/* For wcsdup: align1 and align2 here mean alignment not in bytes,
> +   but in wchar_ts, in bytes it will equal to align * (sizeof (wchar_t))
> +   len for wcschr here isn't in bytes but it's number of wchar_t symbols.  */
> +  align1 &= 7;
> +  if ((align1 + len) * sizeof (CHAR) >= page_size)
> +    return;
> +
> +  align2 &= 7;
> +  if ((align2 + len) * sizeof (CHAR) >= page_size)
> +    return;
> +
> +  s1 = (CHAR *) (buf1) + align1;
> +
> +  for (i = 0; i < len; i++)
> +    s1[i] = 32 + 23 * i % (max_char - 32);
> +  s1[len] = 0;
> +
> +  do_one_test (s1, len);
> +}
> +
> +static void
> +do_random_tests (void)
> +{
> +  size_t i, j, n, align1, align2, len;
> +  UCHAR *p1 = (UCHAR *) (buf1 + page_size) - 512;
> +  UCHAR *p2 = (UCHAR *) (buf2 + page_size) - 512;

This variable is not required (see below).

> +  UCHAR *res;
> +
> +  for (n = 0; n < ITERATIONS; n++)
> +    {
> +      /* align1 and align2 are expressed as wchar_t and not in bytes for wide
> +     char test, and thus it will be equal to align times wchar_t size.
> +
> +     For non wide version we need to check all alignments from 0 to 63
> +     since some assembly implementations have separate prolog for alignments
> +     more 48.  */
> +
> +      align1 = random () & (63 / sizeof (CHAR));
> +      if (random () & 1)
> +	align2 = random () & (63 / sizeof (CHAR));
> +      else
> +	align2 = align1 + (random () & 24);
> +      len = random () & 511;
> +      j = align1;
> +      if (align2 > j)
> +	j = align2;
> +      if (len + j >= 511)
> +	len = 510 - j - (random () & 7);
> +      j = len + align1 + 64;
> +      if (j > 512)
> +	j = 512;
> +      for (i = 0; i < j; i++)
> +	{
> +	  if (i == len + align1)
> +	    p1[i] = 0;
> +	  else
> +	    {
> +	      p1[i] = random () & BIG_CHAR;
> +	      if (i >= align1 && i < len + align1 && !p1[i])
> +		p1[i] = (random () & SMALL_CHAR) + 3;
> +	    }
> +	}
> +
> +      FOR_EACH_IMPL (impl, 1)

As before, there is no need to use the ifunc variant test mechanism. 

> +	{
> +	  MEMSET (p2 - 64, '\1', 512 + 64);
> +	  res = (UCHAR *) CALL (impl, (CHAR *) (p1 + align1));

This test does not make sense: strdup returns a newly allocated buffer on
'res' and you test the 'p2' which is different mmap region.  Just use:

  char *r = strdup (p1 + align1)
  TEST_COMPARE_STRING (r, (CHAR *) (p1 + align1));
  free (r);

Since you can really check out of bounds access (as other string tests do)
without trigger UB.


> +	  for (j = 0; j < align2 + 64; ++j)
> +	    {
> +	      if (p2[j - 64] != '\1')
> +		{
> +		  error (0, 0, "Iteration %zd - garbage before, %s (%zd, %zd, %zd)",
> +			 n, impl->name, align1, align2, len);
> +		  ret = 1;
> +		  break;
> +		}
> +	    }
> +	  for (j = align2 + len + 1; j < 512; ++j)
> +	    {
> +	      if (p2[j] != '\1')
> +		{
> +		  error (0, 0, "Iteration %zd - garbage after, %s (%zd, %zd, %zd)",
> +			 n, impl->name, align1, align2, len);
> +		  ret = 1;
> +		  break;
> +		}
> +	    }
> +	  if (MEMCMP (p1 + align1, res, len + 1))
> +	    {
> +	      error (0, 0, "Iteration %zd - different strings, %s (%zd, %zd, %zd)",
> +		     n, impl->name, align1, align2, len);
> +	      ret = 1;
> +	    }
> +	}
> +    }
> +}
> +
> +
> +int
> +test_main (void)
> +{
> +  size_t i;
> +
> +  test_init ();
> +
> +  printf ("%23s", "");
> +  FOR_EACH_IMPL (impl, 0)
> +    printf ("\t%s", impl->name);
> +  putchar ('\n');
> +
> +  for (i = 0; i < 16; ++i)
> +    {
> +      do_test (0, 0, i, SMALL_CHAR);
> +      do_test (0, 0, i, BIG_CHAR);
> +      do_test (0, i, i, SMALL_CHAR);
> +      do_test (i, 0, i, BIG_CHAR);
> +    }
> +
> +  for (i = 1; i < 8; ++i)
> +    {
> +      do_test (0, 0, 8 << i, SMALL_CHAR);
> +      do_test (8 - i, 2 * i, 8 << i, SMALL_CHAR);
> +    }
> +
> +  for (i = 1; i < 8; ++i)
> +    {
> +      do_test (i, 2 * i, 8 << i, SMALL_CHAR);
> +      do_test (2 * i, i, 8 << i, BIG_CHAR);
> +      do_test (i, i, 8 << i, SMALL_CHAR);
> +      do_test (i, i, 8 << i, BIG_CHAR);
> +    }
> +
> +  do_zero_len_test ();
> +  do_random_tests ();
> +
> +  return ret;
> +}
> +
> +#include <support/test-driver.c>